This invention relates generally to track assemblies for track type work machines and, more particularly, to an idler wheel for a track type work machine.
Conventional track chain assemblies utilized on track type work machines typically include a track chain comprised of a plurality of links that are interconnected by laterally disposed track pins. A track bushing is commonly disposed about the pin and is secured to the links for relative rotation with respect to the pin. The bushing is adapted to engage a drive sprocket that propels the track chain assembly about a frame and ultimately provides the tractive force necessary to power the work machine over the ground to perform various work functions with a work implement (e.g. a bucket or a blade).
The bushing is typically a xe2x80x9crollerxe2x80x9d bushing and is not fixed to the links but rather is allowed to rotate about the pin relative to both the pin and the links. This is done to reduce the wear between the sprocket and the bushings which is known to be quite severe, especially in the abrasive conditions in which track type work machines commonly operate.
Another source of wear on a track chain assembly occurs on the links of the track chain as a result of the interaction of the links with an idler wheel. In particular, the links commonly have a wear rail defined on an inwardly directed surface that engages wear surfaces defined on the idler wheel mounted on the frame. As the track chain rotates about the frame in the above-described manner, the wear rails of the links are continually brought into contact with the wear surface of the idler wheel and are thus subjected to severe wear. This severe wear is increased as a result of continually bringing the generally planar surface of the wear rails into contact with the arcuate idler wheel wear surface. The aforementioned contact results in an arcuate wear pattern being formed on the wear rails of the links. This wear decreases the xe2x80x9clifexe2x80x9d of the track chain assembly and thus increases the maintenance cost of the work machine.
As shown in U.S. Pat. Nos. 1,112,460 and 1,228,709 some track assemblies utilize components which have teeth extending therefrom which facilitate the cooperation between the track chain and these components. However, these assemblies also suffer from several drawbacks. For example, the components having the teeth extending therefrom are positioned outside of the links and therefore are subject to damage from elements (e.g. rocks) present in the work environment of the track chain assembly.
The present invention is directed to overcoming one or more of the problems or disadvantages associated with the prior art.
In accordance with one embodiment of the present invention, there is provided an arrangement for supporting a track chain having a track link, a first bushing mechanically coupled to the track link, and a second bushing mechanically coupled to the track link. The first bushing has a first center point C1 defined thereon. The second bushing has a second center point C2 defined thereon. The first center point C1 is spaced apart from the second center point C2 by a distance D1. The arrangement includes an idler wheel having a circumferentially extending surface defined thereon. The circumferentially extending surface has a first notch and a second notch defined therein. The first notch has a first wall portion. The first wall portion has a first point P1 defined thereon at a first location. The second notch has a second wall portion. The second wall portion has a second point P2 defined thereon at a second location which corresponds to the first location. The point P1 is spaced apart from the point P2 by a distance D2. The distance D1 is greater than the distance D2.
In accordance with another embodiment of the present invention there is provided a track chain assembly. The track chain assembly includes a track link. The assembly also includes a first bushing mechanically coupled to the track link. The first bushing has a first center point C1 defined thereon. The assembly also includes a second bushing mechanically coupled to the track link. The second bushing has a second center point C2 defined thereon. The first center point C1 is spaced apart from the second center point C2 by a distance D1. The assembly further includes an idler wheel having a circumferentially extending surface defined thereon. The circumferentially extending surface has a first notch and a second notch defined therein. The first bushing is positioned within the first notch. The second bushing is positioned within the second notch. The first notch has a first wall portion. The first wall portion has a first point P1 defined thereon at a first location. The second notch has a second wall portion. The second wall portion has a second point P2 defined thereon at a second location which corresponds to the first location. The point P1 is spaced apart from the point P2 by a distance D2. The distance D1 is greater than the distance D2.
In accordance with yet another embodiment of the present invention there is provided a track type work machine. The work machine includes a frame and a work implement mechanically coupled to the frame. The work machine also includes a track chain assembly mechanically coupled to the frame. The track chain assembly has (i) a track link, (ii) a first bushing mechanically coupled to the track link, the first bushing has a first center point C1 defined thereon, (iii) a second bushing mechanically coupled to the track link, the second bushing has a second center point C2 defined thereon, the first center point C1 is spaced apart from the second center point C2 by a distance D1, and (iv) an idler wheel having a circumferentially extending surface defined thereon. The circumferentially extending surface has a first notch and a second notch defined therein. The first bushing is positioned within the first notch. The second bushing is positioned within the second notch. The first notch has a first wall portion. The first wall portion has a first point P1 defined thereon at a first location. The second notch has a second wall portion. The second wall portion has a second point P2 defined thereon at a second location which corresponds to the first location. The first point P1 is spaced apart from the second point P2 by a distance D2. The distance D1 is greater than the distance D2.